Spanish authorities had been experimenting with how far they could push their reliance on renewable energy before the Iberian Peninsula suffered a massive power outage last month, it has been suggested.
As people wait for answers about what caused the dystopian power cut that disrupted tens of millions of lives across Spain and Portugal, several have questioned Spain’s heavy reliance on renewable energy sources as it plans to phase out nuclear reactors.
Spain’s socialist Prime Minister Pedro Sanchez has rejected such criticism, asking for patience while the government investigated the causes of the historic blackout.
Authorities pinned it on a significant and unprecedented drop in power generation.
Now, it has been suggested that Spain’s government was carrying out an experiment before the country’s grid system crashed, The Telegraph reports.
Under said test, authorities had been trialling how far they could push their reliance on renewables as they prepared for Spain’s phase-out of nuclear reactors from 2027.
At the time of the outage, Spain’s electric grid operator Red Eléctrica de España said the blackout had been cause by two significant interruptions in power.
The Spanish Association of Electrical Energy Companies (Aelec), which has criticised the inquiry into the blackout’s cause, said it was not the country’s generators that failed to deliver power to the grid, but rather it was the grid that failed to manage it and then shut down automatically.
Spanish authorities had been experimenting with how far they could push their reliance on renewable energy before the Iberian Peninsula suffered a massive power outage last month. Pictured: People stand inside a supermarket without lights in Burgos on April 28, 2025, amid the outages
People wait for power to resume at a luggage checking site during a massive power cut affecting the entire Iberian peninsula
People listen to the radio through the loudspeakers of the headquarters of catalunya radioPeople outside Barcelona Sant rail station during a massive power cut
The head of Spain’s photovoltaic association, Jose Donoso, had made a similar suggestion earlier this month, telling newsoutlet 20Minutos: ‘It’s a matter of logic; the fact that the entire system goes down because of a photovoltaic plant makes no sense.’
‘We suffered the consequences of a grid disruption, but we didn’t cause it.’
Aelec said the authorities had essentially confined the trial to a 20-second span on April 28, and ignored a series of oscillations in tension that began days earlier and transcended ’emergency’ levels across the peninsula for two hours leading up to the blackout.
The association added that the authorities did not substantiate their claim that it all began with a sudden drop of 2.2 gigawatts in power supplied to the grid, which is what they claim set off the chain reaction.
It comes after the sweeping power outage that hit Spain and Portugal last month raised questions about the electricity grid in a region not normally known for blackouts.
The outage, said to be one of the worst ever in Europe, started on the afternoon of April 28 and lasted through nightfall, affecting tens of millions of people across the Iberian Peninsula.
Offices closed and traffic was snarled in Madrid and Lisbon, while some civilians in Barcelona directed traffic. Train services in both countries stopped.
It disrupted businesses, hospitals, transit systems, cellular networks and other critical infrastructure.
Emergency services and rail workers in Spain had to help evacuate some 35,000 people from over 100 trains that stopped on the tracks when the electricity was cut.
Spain generated nearly 57% of its electricity in 2024 from renewable energy sources like wind, hydropower and solar, according to Red Eléctrica.
About 20% came from nuclear power plants.
Spanish Prime Minister Pedro Sanchez pictured last month
A traveller raise her phone up to catch network inside Barcelona-Sants rail station during a massive power cut affecting the entire Iberian peninsula and the south of France, in Barcelona on April 28, 2025
Millions were left without power as public transport and roads ground to a halt in April
People get off a stopped high-speed AVE train near Cordoba on April 28
This photograph shows traffic jam in downtown Madrid during a massive power cut
In 2019, Sánchez’s government approved a plan to decommission the country’s remaining nuclear reactors between 2027 and 2035 as it expands its share of renewable energy even further.
The country aims to generate 81% of its electricity by 2030 from renewable sources.
It is rare to have such a widespread outage across the Iberian Peninsula, with a combined population of about 60 million people.
Spain’s Canary Islands, Balearic Islands and the territories of Ceuta and Melilla, located across the Mediterranean in Africa, were not affected.
